Electrostatic relays and controls



y 1959 J. w. DIESEL 2,885,509

ELECTROSTATIC RELAYS AND CONTROLS Filed March 12, 1956 2 Sheets-Sheet 1 FIG. I H6 2 o -22 I 0 Q a 6 W M 1 JOHN M D/ESEL,

y 5, 1959 J. WIDIESEL O 1 2,885,509

' ELECTROSTATIC? RELAYS AND CONTROLS Filed March 12, 1956 I 2 Sheet-Sheet 2 FIG; IO

JOHN W. DIESEL United States Patent t) ELECTROSTATIC RELAYS AND CONTROLS John W. Diesel, Maplewood, Mo., assignor to Erdco, Inc., Maplewood, Mo., a corporation of Missouri Application March 12, v1956, Serial No. 571,098

16 Claims. (Cl. 200-87) This invention relates to electric controls, and more particularly to electrostatic relays of the type disclosed in my copending application, Serial No. 441,057, filed July 2, 1954, of which this is a continuation-in-part.

In my prior application, I have disclosed an electrostatic relay structure which would be suitable for use in digital computers, business machines and the like. The present application is directed to a simplified and improved form of this relay. For example, the present relay might be made with as little as four parts; namely, a base panel, a fixed-contact panel or frame, a relay-arm panel, and an overlying spacer frame, the base panel of an overlying relay serving as the top of an underlying relay. The base panel carries fixed plates on both its top and bottom surfaces, which plates are continuously energized. The relay-arm flap is similarly coated on both its upper and lower surfaces with conductive material so as to provide a movable plate cooperable with the fixed plates. In other words, this type of relay employs an electric bias, as contrasted with a gravity or spring bias to hold the relay arm in what would normally be an unexcited or off position.

The invention further contemplates an improved arrangement of contacts wherein the fixed contacts are grouped in pairs adapted to be bridged by movable contacts. The fixed contacts may be formed as resilient fingers of springy insulating material with contact elements on the ends of the fingers. For example, the contacts may be made by laminating a strip of contact material, such as stainless steel, to a plastic panel and then cutting a saw-tooth edge so as to leave a row of separate contacts. Printed circuit leads may extend across the panel from the fixed contact elements.

For convenience in making connections with one or more relays, the panels are stacked together to form a block, and one of the panels has a lead-carrying portion projecting from one side of the block. This projecting portion may then be registered with a lead-carrying bus of plastic or with a similar portion from another relay block, the connection between the several leads on the two pieces being in registered pressure engagement. Also, certain conductors from a group of lines extending across one face of a panel may be selectively connected through cross-over" holes to a second set of conductors extending over the other face of the panel.

Finally, the invention contemplates high-resistance plates, such as might be formed of carbon ink or paint, will be broken or subdivided along lines which extend at right angles to the low-resistance leads for the plates and to the hinge line of the relay arm. The relay arm preferably is so thin, it lacks the resilient or spring efiect mentioned in my prior application.

2,885,509 Patented May 5, 1959 Other features of the invention will be in part apparent from and in part pointed out in the following detail description taken in connection with the accompanying drawings, in which:

Fig. l is a circuit diagram illustrating the plate circuit of an electrostatic relay such as might be used for address, arithmetic and temporary storage purposes;

Fig. 2 is a vertical section illustrating portions of several such relays as they would be assembled in a stack, thicknesses being exaggerated;

Fig. 3 is a top plan view of the base panel of the Fig. 2 relay;

Fig. 4 is a top plan view of a lower spacer frame;

Fig. 5 is a top plan view of the overlying fixed-contact panel;

Fig. 6 is a bottom plan view of the overlying relayarm panel;

Fig. 7 is a top plan view of the relay-arm panel;

Fig. 8 is a top plan view of the spacer frame;

Fig. 9 is a bottom plan view of the base plate, which forms the top of an underlying relay unit when several units are stacked one upon the other;

Fig. 10 is a top plan detail of a wiring panel showing how the contact leads might be separated into a set of input conductors and a set of output conductors;

Fig. 11 is a side elevation illustrating how relay units may be stacked one upon the other with lead-carrying projecting portions connected to a main bus;

Fig. 12 is a top plan view of a main bus, showing how the terminal ends are connected while the intervening portion is coiled as a flexible multiple-conductor cable; and

Fig. 13 is an enlarged sectional view taken generally on the line 13-13 of Fig. 12 to illustrate the connections between overlapping panels.

Referring now to Fig. l of the drawings, there is shown a relay suitable for general switching purposes. The relay is formed with upper and lower fixed plates, designated P1 and P2, respectively. These plates are formed of high resistance material, such as carbon paint, sprayed or otherwise disposed upon relatively fixed panels of insulation. The fixed plates are spaced apart vertically to accommodate a movable plate MP, the opposite faces of which are conductively cooperable with the respective fixed plates. For example, there may be a relay arm of thin flexible plastic faced on both sides with a low resistance material, such as silver paint or conductive foil. The relay arm is hinged at one end HE so that the opposite end FE is free to move from one fixed plate to the other. The secondary circuits and associated contacts are not shown in Fig. l, which is primarily directed to the plate or excitation circuit of the relay, but the relay may be provided with a hold circuit including a movable hold contact mounted on the free end of the relay arm and connected to the movable plate for cooperation with a fixed contact. These contacts form a part of a hold circuit HC.

The lower fixed plate P2 is connected to ground adjacent the free end of the movable plate through a plate resistance R2, whereas the upper fixed plate P1 is connected to the positive side of a high-voltage supply through a plate resistance R1. Such plate resistance may be separate from the plates as R2 or may be represented by extensions of the high-resistance coatings that form the plates as R1. The resistance values may vary considerably, but it is preferable for the upper plate P1 to 'nected to the power supply.

have a resistance higher than that of the lower plate P2. The movable plate MP is connected through a normallyopen actuating switch AS to the positive terminal of the voltage supply, and a release resistor R3 is connected to ground between the switch AS and the movable plate. The holding circuit is also connected through a second normally-closed switch HS to the positive side of the voltage supply. It should be understood that AS is symbolic only, and may represent a circuit closed through a complex set of contacts of similar relays and finally to the power supply.

As explained in my prior application, the relays are operated with DC. signals of high voltage and low current. For example, the voltage may be on the order of two thousand volts ,While the current is limited to a tenth of a milliamp and preferably less. For example, the effective plate resistance R1 (as determined by the point of contact between the movable plate MP and the upper fixed plate) could be one thousand meg'ohms.

Similarly, the effective plate resistance R2 could be one hundred megohms or more. The resistance at release resistor R3 cannot be too high; else the relay will open slowly, at value of fifty megohms being suggested. The high resistance plates are formed of carbon paint having predetermined resistance and are spaced about one-sixteenth of an inch vertically from one another.

In operation, the upper fixed plate P1 is normally positive whereas the lower fixed plate P2 is normally negative. The movable plate MP initially has a negative charge since it is connected to ground through release resistor R3. Accordingly, the movable plate is attracted by and held against the upper positive fixed plate P1. When the switch AS is closed, the movable plate receives a positive charge, whereupon it is repelled by the upper plate P1 and attracted by the lower fixed plate P2. The movable plate is pulled downwardly until a portion thereof engages the lower plate or otherwise completes a circuit between the plates MP and P2. At that time, the contacts for the hold circuit are closed, thereby completing a circuit from the positive terminal through the normally-closed switch HS, so that the movable plate remains positive, although the actuating switch AS is subsequently opened. 1n the actuated or downward position, as viewed in Fig. 1, contacts for the secondary circuit (not shown) would be actuated by the free end of the relay arm. Also, it should be understood that switches AS and HS may be operated by similar relays.

When it is desired to release the relay, the hold switch HS is opened, it being assumed that the actuating switch AS has been opened previously. When the hold circuit is broken, the'movable plate MP is drained of its positive charge through the release resistor R3. Accordingly, the movable plate is repelled from the negative fixed plate understanding of the theory'of operation and basic princi'ples'of construction. Briefly, the point of contact of "th'movable plate with either fixed plate should occur inwardly from the ends, where the fixed plates are con- Consequently, a voltage drop should occur across a portion of the fixed plate, so that the movable plate will be held in proper position.

Referring now to Figs. 2-8 more specifically, the relays are designed so that they may be stacked one upon the other for convenient assembly. Each relay comprises a base panel 1, a contact panel 3, a relay-arm panel 5 and spacer' frames 6 and 7, all formed of insulating material.

The base 1 may be a rectangular sheet of laminated phenolic or other inexpensive reasonably stiff insulation. Its upper face is coated with a carbon paint so as v to form one or more high-resistance areas 9, and its lower face is similarly coated with high-resistance paint to form additional conductive areas 11. It will be noted that the plate areas may be subdivided along lines 12, which extend front to back. For purposes of explanation, the areas 9 will be referred to as the fixed negative plate, they being permanently connected to the negative side of the voltage supply, whereas the areas 11 are permanently connected to the positive terminal and will be referred to as the fixed positive plate.

A low-resistance lead 13 of silver paint or foil running along the front portion of the negative plate is connected to a line 15 at one side. The plate resistance R2 is formed by the fixed plate itself in the sense that its point of contact with the associated movable plate will occur rearwardly from the low-resistance lead 13. The lead 15 is then connected to a terminal16 at the back of the panel. The positive fixed plate 11 on the opposite face of the base panel is connected along its front and back portions with low-resistance leads 17, which are connected together M19 and toaterminal 21. As before the effective plateresistance Rlis formed by the plate.

The fixed-contact panel 3 is spaced over the base 1 by a frame 6, and its center portion is cut away at 23 to expose the negative fixed plate 9. Fixed contacts are-then formed along the front margin of the opening for cooperation with contacts on the relay arm. The contacts may be conveniently formed by adhering a strip of stainless steel or other contact material to the panel. A sawtooth cut is then made along'the metal strip in cutting the opening 23 so asto leave a row of spaced metalfaced contact fingers 24 and 25. Finally, leads 26, 27 and 28 of low-resistance foil or silver paint extend forwardly from the contacts.

In the disclosed embodiment, the contact panel 3 may be a sheet of polyester resin, such as Mylar, the front portion 30 of which projects forwardly from the relay unit for conductive connection with similar elements, as will be described. The back portion of the panel has a cross-over hole 32 filled with conductive material and positioned to register with the terminal leads 16 of the underlying base panel through a'similar hole 22 in the frame 6.

The relay-arm panel 5 overlyingthe contact panel should be light and flexible, hence it may be formed of very thin (one-thousandth of an inch) Mylar. The back portion of the panel is adapted to project at 34 rearwardly from the relay unit. U-shaped cuts 29 are otherwise made in the panel so as toform flaps 31, which are hinged at the back. Several flaps are provided in order to minimize the air cushion effect. H Each flap 31 is doublefaced with low-resistance material "so as to form bottom conductive areas'33 'cooperable with'the negative plates 9 and top'conductive' areas35 -cooperable with positive plates 11. The 'areas'33 are "connected'together by a 'low-resistance'lead 37', and areas'35 are similarly con nected together by alead' '36. The areas 33 and "35 are "connected by'leads36'and 37'toone"of agroup of-plat input conductors 39 "on' each face of the panel Each lead 39'on one face is connectedtocorrespondinglead movable plate.

The movable plate'areas can be formed by silver paint or by laminating a thin foil of conductive metal to the plastic. Another process involves the use of metallized Mylar, which has a'very thimmetalcoating deposited under vacuum from a vapor pan. The plate areas and leads could be controlled by stencil, or an etching step could remove undesiredportions of an over-all coating. If necessary, the thermal vacuum deposit layer could be further built up by electroplating. Preferably, the relay arm should be as thin as possible, at least to an extent such that it has slight if any resilient tendency to spring back by itself.

The low-resistance leads 36 and 37 are also connected to high-resistance lines 41 forming the release resistor R3 previously referred to. Resistors 41, in turn, are connected through low-resistance leads 43 extending rearwardly on the panel 5, which may be connected together through a cross-over hole 40. The lead 43 is positioned so as to make contact with cross-over holes 22 and 32, which are registered with terminal 16 on the base panel. Panel 5 is also provided with a second low-resistance lead 45, which is positioned to register with a cross-over hole 42 in the spacer frame 7 and terminal 21 of the upper fixed plate. Lead 45 is ultimately connected to the positive terminal of the voltage supply, whereas lead 43 is connected to the negative terminal. A third lead 44 having cross-over hole 46 extends around to the front of the relay arm panel for registered connection with contact leads 26 which are connected together by cross-over holes 48 and a conductive line 50 on the bottom face of the contact panel 3. Lead 44 is the input for the hole circuit referred to previously.

The free ends of the flaps are provided with metallicfoil contacts 49 and 51 similar to and cooperable with the fixed contact fingers 24 and 25 on the fixed-contact panel. The opposed contacts 24 and 49 form a holding circuit, the movable contacts 49 being connected directly to the movable plate.

The more numerous movable contacts 51 are relatively wide so as to bridge pairs of fixed contacts 25, each pair of fixed contacts having associated leads 27 and 28 to form a secondary circuit. The leads 27 could be referred to as input conductors, whereas the leads 28 are referred to as output conductors of the secondary circuits.

Finally, spacer frame 7 is sandwiched between the margins of the relay-arm panel 5 and an overlying base 1, so as to provide a space wherein the movable plate may move from one to the other of the fixed plates. The separation of the fixed plates might be on the order of one sixteenth to one thirty-second of an inch. It will be noted that the base panel 1 may form the bottom of one relay and the top of an underlying relay, thereby conserving material, but there must be two base panels 1 in order to complete a relay. In some instances, it may not be necessary to provide an additional spacer frame 6 between the base and the fixed-contact panel, but this frame 6 permits the fixed contact fingers 24 and 25 to project in free space as resilient or spring fingers. Such an arrangement minimizes contact bounce and helps to insure that all secondary circuits are closed when the relay is excited.

Fig. illustrates how cross-over holes 52 may be utilized to separate the contact input conductors 27 from the contact output conductors 28. For example, the portion of the panel shown in Fig. 10 may be the extension 30 from the contact panel 3. Cross-over holes 52 then connect with a set of conductive lines 54, which extend transversely across the back face of the insulation 30 to an extension 56. Conductors 58 on its front surface can then be connected to the conductive lines 54 by crossover holes 60.

The several panels are stacked together to form a relay, and several relays may be stacked together, as indicated in Fig. 11. Corner holes 47 in the panels facilitate such assembly, rods 49 being employed to hold the panels in assembly. The stacked panels are shown to be mounted on a base 51 and secured by a cap 53, which compresses the panels into tight engagement. The outer side edges of an assembled block can then be sealed by lacquer.

A number of relays might be assembled on a main base panel, which itself carries printed leads, or two units could be connected together by means of a flexible bus, as shown in Fig. 12. A thin strip 53 of plastic has a plurality of spaced parallel leads 55 extending longitudinally over one surface. One end of the strip 53 may have a similar pattern of short terminal leads 59 on the other face, which are connected to leads 55 through cross- I over holes 57. One flat end of the strip is pressed into registered engagement with a similar pattern of conductive lines 61 on insulating panels 63. Each panel might have leads 61 on both faces connected by cross-over holes 65. The leads 61 might be continuations of the input excitation leads 39, for example. The other end of strip 53 can be similarly connected to another unit, whereas the intervening center portion of the strip 53 is rolled up and secured at 59, to form a flexible cable.

From the foregoing description, it is apparent that those skilled in the art will understand the structure, function and mode of operation of the invention herein disclosed, and appreciate the advantages thereof. Although one embodiment has been disclosed in detail, it is to be understood that the invention is not limited thereto, but the drawings and description thereof are to be understood as being merely illustrative. It is realized that many modifications and variations will present themselves to those skilled in the art without departing from the spirit of this invention or the scope thereof as set forth in the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In electrostatic relay apparatus constituted by a plurality of insulating panels having conductive plateforming areas and contact leads thereon; the improvement that comprises a block of said panels stacked together, and a flexible strip of insulating material projecting from said block, said strip having a plurality of spaced parallel conductive lines extending longitudinally across one face thereof, the conductive lines on said strip being electrically connected to the contact leads of one of said panels.

2. Electrostatic control apparatus as set forth in claim 1, wherein said flexible strip is in part rolled, and means securing said rolled portion of the strip to form a flexible multiple-conductor cable.

3. In an electrostatic relay having a pair of opposed conductive plates, one of which is relatively movable toward and away from the other; the improvement that comprises one of the plates being formed as a highresistance conductive area on a panel of insulation, a relatively low-resistance conductive line extending along one edge of said high-resistance area, said high-resistance area being subdivided along lines extending at right angles .to said low-resistance line.

4. In an electrostatic relay having a pair of fixed plates mounted in opposed spaced relationship and a relay arm mounted for movement therebetween; the improvement that comprises said relay arm being constituted as a thin generally rectangular panel of plastic, means clamping one margin of said relay arm panel to form a hinge, the two adjacent margins of the relay arm being free so as to permit movement of the center portion between the fixed plates, the center portion of said relay arm having conductive areas on both faces electrostatically cooperable with the respective fixed plates, the hinged portion of said relay arm being suificiently limp and the center portion of the relay arm being sufficiently light in weight so that the operative bias of the relay arm is substantially entirely electrostatic.

5. A block-like assembly of multiple-pole electrostatic relays, the relays being relatively thin panel-like structures stacked one upon the other; and each relay comprising a relatively rigid panel extending across the block, said panel having a conductive plate-forming area on one surface, spacer means at opposed margins of said panel on the conductive surface thereof, a second relatively rigid panel spaced above said first panel and extending across said block, said second panel having spacer means at opposed margins thereof, a relay arm sandwiched between said spacer means at one margin of the block, said relay arm being relatively flexible at said margin so as to provide a hinge joint, and contact means disposed between the spacer means at the opposite margin of the.

fblock for cooperation with the" free end ofthe relay arm.

/ 6. Apparatus asset forth in claim further including contact leads connected 'to'said contact means of the relays and projecting from said block at said one sidethereof.

7. An electrostatic relay formed as a thin panel-like structure comprising upper and lower spaced parallel panels defining the'top and bottom of 'said' relay, upper and lower spacer members of insulating material sandwiched between the upper and lower panels at the margins thereof, thereby to space the panels and define an open center area, said lower panel having a conductive upper surface and said upper panel having a plate-forming lower surface, both conductive surfaces extending over a substantial portion of the'open center areas of the panels, a flexible relay arm panel having a marginal portion thereof sandwiched between the upper and lower spacer'members along'one'margin of the relay and a movable portion disposed within the center open space of the relay, said relay arm panel having top and bottom conductive plate-forming surfaces opposite the conductive surfaces of said top and bottom panels, said relay arm panel thereby being movableunder electrostatic force toward either the top or bottom'panel, and contact means in said center open space actuated by the movable portion of the relay.

8. A relay as set forth in claim 7, wherein said relay arm is secured between the spacer members along only one margin thereof, contact means being secured to the opposite margin of said relay arm, and second contact means sandwiched between the spacer members adjacent said opposite margin of the'relay arm to project within said center open space for cooperation with the contact means carried by said relay arm.

9. A relay as set forth in claim 7, wherein said contact means includes at least two fixed contact members secured opposite a movable portion of said relay arm in spaced adjacent relationship to one another, and a relatively larger movable contact mounted on said relay arm in position to bridge said two fixed contacts upon movement of the relay arm toward said fixed contacts.

10. An electrostatic relay comprising a base, a spacer disposed above said base, a relay arm overlying said spacer, a second spacer overlying said relay arm, and a second base disposed above said second spacer, all of said.

members being formed of insulating material, a lower fixed plate of conductive material formed on the top surface of said first base, an upper fixed plate of conductive material formed on the bottom surface of said second base, movable plate-forming areas of conductive material formed on both top and bottorn surfaces of said relay arm, said relay arm being movable between said two fixed plates, electrical leads extending from the several plates across said insulating members, said insulating members being stackedtogether to form a block-like relay structure, and at least one of said insulating members having electrical leads extending outwardly thereacross, said lead-carrying portion of said member projecting from one side of the block.

11. In an electrostatic relay of the type having a rela tively fixed conductive plate and a relay arm mounted in spaced relationship opposite said fixed plate and having a conductive surface opposed to said fixed plate; the

\ siliently yielding cooperation with the movable end of the relay arm.

l2."Anelectrostatid'relay' as' set forth in' claim '11,

'further including a movable contact mounted'on'the movable endof said relay arm in position to bridge a pairof said contact fingers, which project inwardly therebeneath.

13; An electrostatic relay comprising a block-like structure of "s't'ack'edpanels, comprising spaced top and bottom panels,'at"least one of which has a conductive plateforming 'inner' surface, a relay-arm panel disposed between the top and bottom panels, said relay arm panel havinga free end'margin' movable between said top and bottom panels and having a conductive plate-forming surfaceopposed to said other plate-forming surface, a fixed- 'contact panebdisposed' between the top and bottom panels and having an inner margin disposed beneath the free end marginof'said relay-arm panel, said fixedcOntact'paneI being formed of insulating material and fixed-contact panel being formed with spacedfinget-l'ike projections,-the contact members being metallic elements secured to the ends of said finger-like projections, and

'the 'insulating panel being formed of resilient material to support said metallic contact elements in resilientlyyielding independent relationship from one another.

14, An electrostatic relay comprising a block-like structure ofstacked panels, comprising spaced top and bottom fixed panels, 'at' least one of which has a conductive plate-forming inner surface, a relay-arm panel disposed between said top and bottom panels, said relay arm panel having a'free end margin movable between said topand bottom panels and having a conductive plate-forming surface opposed to said other plate-forming surface, a

fixed-contact panel disposed between the top and bottom l panels and having an inner margin disposed beneath the free end' margin of' said relay-arm panel, said fixedcontact panel being formed of insulating material and having contact elements disposed along said inner margin in spaced relationship from one another, and contact leads extending from said contact elements outwardly in parallel relationship to'one another across one face forming mner surface, a relay-arm panel dlsposed between the'top and bottom panels, said relay arm having 1 a free en d'margin movable between said top and bottom of said insulating member, said lead-carrying portion of the fixed contact panel projecting outwardly from one side of the block-like structure.

15. An'electrostatic relay comprising a block-like structure of stacked panels, comprising spaced top and bottom fixed panels, at least one of which has a conductive platepanels and having a conductive plate-forming surface :cp'posed to said other plate-forming surface, a fixedcontact panel'dis'p'osed between the top and bottom panels 1 and the panel having an inner margin disposed beneath the free end margin ofsaid relay-arm panel, said fixedcontact panel being formed of insulating material and having contact elements disposed along said inner margin in spaced relationship from one another, and contact leads extending from said contact elements outwardly in parallel relationship to one another across one face of said insulating member, a second set of spaced parallel conductive'leads extending across the' other face of the spacer, and an overlying relay-arm panel having a plateforming conductive lower surface, the base panel of one relay serving as the top panel for the relay immediately therebelow, thereby achieving a compact inexpensive multiple-relay structure.

References Cited in the file of this patent UNITED STATES PATENTS 1,403,701 McCullough Jan. 17, 1922 10 10 Lewin Oct. 10, 1939 Kinsley June 4, 1940 Mason Dec. 31, 1940 Eisler Apr. 7, 1953 Shewmaker June 26, 1956 Crownover July 23, 1957 FOREIGN PATENTS Great Britain Aug. 9, 1923 Great Britain Nov. 17, 1932 

